Process of making low fat low cholesterol milk products

ABSTRACT

The present invention relates to a low cholesterol, low fat milk that has the taste and mouthfeel of whole milk or 2% milk. The invention also relates to use of said aformentioned milk to produce low cholesterol, low fat dairy products.

This is a continuation of application Ser. No. 472,018 filed Jan. 30,1990, now U.S. Pat. No. 5,063,074.

BACKGROUND OF THE INVENTION

The current wave of increased awareness by the public of the healthrisks associated with saturated animal fats and cholesterol hasaccelerated the demand for palatable low fat dairy products. As aresult, attempts have been made to develop low fat systems with themouthfeel of higher fat products.

Arndt, U.S. Pat. No. 3,843,828 discloses a simulated milk productcomprising an isolated vegetable protein, whey, and hydrogenatedvegetable oil.

Zeller, U.S. Pat. No. 4,631,196 describes a low cholesterol, lowcalorie, no fat dairy product wherein polydextrose is added to skim milkto provide sweetness and mouthfeel.

Bookwalter et al, U.S. Pat. No. 4,842,884 describes a formulated milkconcentrate prepared using nonfat dry milk and vegetable oil, whereinthe ratio of nonfat milk solids to water is such that no emulsifiers arerequired to emulsify the oil.

In addition to dairy products that are low in fat and cholesterol, thereare also increasing demands for products fortified with vitamins and/orminerals. Research in the area of fortification of dairy products hasconcentrated on development of methods whereby the product can beenriched while maintaining its natural flavor and mouthfeel.

Toward this end, Nelson, et al., U.S. Pat. No. 4,701,329 describe acalcium and phosphate enriched fortified milk comprising calcium,tribasic calcium phosphate, carageenan and guar gum having acceptablemouthfeel and flavor. The combination of carageenan and guar gummaintain the suspension of the calcium thus permitting the production ofa milk product having the taste and mouthfeel of unfortified milk.

Similarly, Karinen, U.S. Pat. No. 4,803,087 describes enrichment of milkby adding to raw milk, prior to cream separation, pasteurization andhomogenization, an aqueous emulsion of edible oil, vitamins A and D, andan emulsifier comprising polyoxyethylene sorbitan monooleate andglycerol monooleate.

Despite the developments of the above substitute dairy products, therehas not, as yet, been developed a method whereby a skim milk product canbe produced that has the taste and mouthfeel of whole or 2% milk.

SUMMARY OF THE INVENTION

These and other objects are achieved by the present invention, wherebyskim milk is combined with a premix comprising a vegetable oil carrieras well as agents which impart texture and flavoring properties to themilk product. The resultant fluid milk has a taste and mouthfeel whichapproximate that of whole or 2% milk, while having negligible animal fatand cholesterol. With adequate pasteurization, it can be stored atrefrigerated temperatures for at least six weeks. Alternatively, thefluid milk can be used to produce a number of low fat, low cholesteroldairy products such as yogurt, cheeses, and buttermilk.

DETAILED DESCRIPTION OF THE INVENTION

The milk product of the present invention is prepared by combining apremix with skim milk. As contemplated by the invention, the premix isessentially a flavoring agent dispersed in a vegetable oil carrier. Mostpreferably the flavoring agent is emulsified or dispersed in thevegetable oil with the aid of emulsifiers and/or gums. The premix may beadded to skim milk at a level of 1 to about 5% by weight; mostpreferably it is added at a level of about 1.5 to 2%.

In representative formulations of the present invention, the premixpreferably comprises about 50 to about 70% non-tropical vegetable oil,about 6 to about 10% emulsifier, about 15 to about 20% gum and about 6to about 10% flavoring agent. Most preferably, the premix comprisesabout 60% non-tropical vegetable oil, about 8% emulsifier, about 18% gumand about 8% flavoring agent. It may further comprise additionalvitamins and/or minerals, such as calcium, at levels of up to 20% byweight.

Throughout this application, all amounts are by weight unless expresslystated otherwise. In addition, percentages are on a total formulationbasis unless another basis is specified.

Any non-tropical vegetable oil may be employed in practicing the presentinvention. Most preferably, a nonlauric oil is chosen which is tastelessand odorless, and which remains so during extended storage of theproduct. Such oils are selected by their non cholesterolemic orhypocholesterolemic properties. Suitable oils include soybean,safflower, corn, cottonseed, sunflower, peanut, olive and canola oils orany combination thereof.

The emulsifier component is most preferably comprised of a mixture of35-54% mono and diglycerides, 23-43% sodium stearoyl lactylate and12-32% polysorbate 60. Alternatively, any non-lauric emulsifier approvedfor food use and exhibiting similar emulsifying properties can be usedto produce the milk product of the present invention. These may includehydroxylated lecithin, mono, di or polyglycerides of fatty acids, suchas monostearin and monopalmitin; polyhydric alcohols, such as thepolyoxyethylene ethers of sorbitan monostearate (polysorbate 60 or 80)or the polyoxyethylene ethers of sorbitan distearate; fatty ethers ofpolyhydric alcohols such as sorbitan monostearate; mono and di-esters ofglycols such as propylene glycol monostearate, and propylene glycolmonopalmitate, succinoylated monoglycerides; sodium or calciumstearoyl-2-lactylate; and the ethers of carboxylic acid such as lactic,citric, and tartaric acids with the mono and diglycerides of fatty acidssuch as glycerol lactopalmitate and glycerol lactostearate. The fattyacids employed in the preparation of the emulsifiers include thosederived from beef, tallow, and coconut, cottonseed, palm, peanut,soybean and marine oils. Many blends of emulsifiers are commerciallyused and readily available in accordance with known techniques.

The premix is preferably comprised of about 15 to about 20% stabilizersand/or gums which prevent settling and/or emulsify the flavoringcomponent in the premix and which further provide mouthfeel in the finalproduct. Most preferably, a combination of about 93 to about 97%microcrystalline cellulose and about 3 to about 7% carageenan is used tocreate a mouthfeel most similar to whole or 2% milk. Other gums orstabilizers which exhibit similar properties may be employed inpracticing the present invention. These include sodiumcarboxymethylcellulose (CMC), guar, locust bean, acacia, carageenan orother naturally derived or modified gums, biologically produced gumssuch as xanthan, or modified starches, appropriately modified for theparticular use.

The premix is further comprised of flavoring agents, which may includeany or all of the following: chocolate, vanilla, strawberry, coffee,mocha, banana or any other suitable flavoring at a level of about 6 toabout 10%. Most preferably, the flavoring agent comprises a mixture ofnatural vanilla and natural milk distillate, wherein the natural milkdistillate comprises between about 70 and about 90% of the flavoringagent. Natural milk distillate is a commercially available distillate ofwhole milk.

The premix may also comprise additional vitamins or minerals for thepurpose of fortification. Most preferably, calcium in the form oftri-calcium phosphate, calcium lactate, orthophosphates, calciumchloride or any other suitable form may be added to the premix at alevel of 15 to about 20%.

The premix is prepared by combining the vegetable oil with a flavoringagent. Most preferably, the flavoring agent is suspended or emulsifiedin the vegetable oil using emulsifiers and stabilizers. The premix soprepared is then added to skim milk with mixing at 130° F. until thepremix is completely dissolved in the milk. The mixture is thenpasteurized using either a UHT (ultra high temperature) treatment, atabout 180°-240° F. for about 2 to 5 seconds, or using a high temperatureshort time (HTST) process, which is accomplished at about 161° F. forabout 15 seconds. Following pasteurization, the product is homogenizedat 500/2500 psi range total 1500-3000, cooled and packaged.

The milk product so produced is suitable for immediate consumption inplace of milk. Alternatively, the product can be further processed toproduce a number of dairy products with lower fat and cholesterolcontents than their counterparts made from whole milk. It has beenfound, for example, that yogurt, buttermilk, cheddar cheese and cottagecheese made using the milk product prepared as described above havesimilar flavor and textural characteristics to similar products madewith low fat milk.

The invention will be more fully understood in the light of thefollowing examples which are set forth below for illustrative purposesonly and are not intended to be limiting.

EXAMPLES EXAMPLE 1

Illustrative of the dairy product that can be made according to theinvention is a low cholesterol, low fat milk product wherein about 1 toabout 5% by weight of a premix is added to skim milk. The premix isessentially a mixture of about 50 to about 70% non-tropical vegetableoil, about 15 to about 20% gum, about 6 to about 10% emulsifier, andabout 6 to about 10% of a flavoring agent. The flavoring agent in thisexample is a mixture of vanilla flavoring and natural milk distillate, aflavor distillate of whole milk.

The formulation used to prepare the premix in this example was:

    ______________________________________                                        Ingredient           Weight(grams)                                            ______________________________________                                        soybean oil          .984                                                     tri-calcium phosphate                                                                              .300                                                     microcrystalline cellulose                                                                         .250                                                     mono and diglycerides                                                                              .056                                                     sodium stearoyl lactylate                                                                          .042                                                     polysorbate 60       .028                                                     carageenan(kappa)    .015                                                     natural milk extract .100                                                     natural vanilla 5X   .020                                                                          1.795   grams                                            ______________________________________                                    

To 98.205 grams of skim milk (Vitamin A and D added) were added 1.795grams of premix which were mixed at 130° F. until the premix wascompletely dissolved in the milk. The mixture was then pasteurized at161° F. for 15 seconds (HTST) or at 180°-240° F. for 2 to 5 seconds(UHT). Following homogenization at 500/2500 psi range total 1500-3000psi, the product was 28 cooled through a heat exchanger to 32°-40° F.and packaged. The product so produced was stored at 36° to 40° F. indistribution. Product that received the HTST pasteurization had a shelflife of about two weeks, wherein product that was processed under UHTconditions had a shelf life of at least six weeks.

EXAMPLE 2

The milk product produced in Example 1 was sterilized, cooled at roomtemperature and inoculated with lactic acid bacteria (L. bulgaricus ATCC11842 and S. thermophilus ATCC 14485; 50:50 ratio) at 5% by weightlevel. The product was incubated at 43° C.±1° C. for 16 hours. Thecomplete yogurt flavor is obtained because lactobacilli are grown inassociation with the moderate acid producing Streptococcus thermophilusspecies. The lactobacilli, in turn, during their growth liberate aminoacids which stimulate S. thermophilus growth. The streptococci, inaddition, produce formate as a metabolic byproduct which enhances thegrowth of the lactobacilli. Analysis of the yogurt products producedusing the milk product as described in Example 1 as well as regular milkare set forth in Table 1. As can be seen from the data describedtherein, the yogurt made with the Example 1 milk was slightly lessacidic compared to yogurt made with regular milk. The flavor of theyogurt made with the Example 1 milk was acceptable, and it had a smooth,light custard texture.

                  TABLE 1                                                         ______________________________________                                        Analysis of yogurt made with control (whole) milk                             and Example 1 milk product                                                                           Example 1                                                              Control                                                                              milk                                                   ______________________________________                                        Fat (Mojonnier)   3.42%    1.17                                               Solids (100C/Vacuum)                                                                            12.09%   10.47                                              Protein           3.16     3.15                                               PH                3.76     4.12                                               TTA(% lactic)     1.35     0.91                                               Brookfield Viscosity                                                                            590      370                                                (CPS @ 65F)                                                                   Needle 4                                                                      Speed 50                                                                      A 250 ML beaker used because of low amount of sample.                         ______________________________________                                    

Production of Cottage Cheese

Milk made according to Example 1 was pasteurized (79° C. for 5 minutes),cooled to 20° C. and inoculated with lactic acid starter culture. Theculture contained S. lactis at a 5% level by weight and 0.2% by weightrennin was also added. The rennin allows the curd to be cut at slightlyhigher pH and also provides a sweeter curd. After adding the culture andrennin, the mixture was incubated at 32° C.±1° C. for 5 hours (short-setmethod). After fermentation, the curd was heated at 38° C. for 40 to 45minutes and washed thoroughly with water at 20° C. A control was alsorun (1% lowfat milk). The resultant products were analyzed. The dataregarding cottage cheese samples are set forth in Tables 2 and 3. Dataregarding the whey produced from the cottage cheese (the data for whichis set forth in Table 2), is presented in Table 4. The cottage cheesemade with the Example 1 milk had a delicate flavor and texture similarto and characteristic of good quality cottage cheese.

                  TABLE 2                                                         ______________________________________                                        Analysis of Cottage Cheese Samples                                            Sample                              Brookfield                                Test   Information                                                                              PH     TTA  Solids                                                                              Viscosity*                                                                            Fat                               ______________________________________                                        1      Example 1  4.10   0.9  10.48 840     1.16                                     milk                         412                                       2      Whole Milk 3.77   1.4  11.73 920     3.38                                                                  508                                       3      1% Milk Fat                                                                              3.67   1.3. 9.85  800     1.07                                                                  440                                       4      2% Milk Fat                                                                              3.74   1.3  10.20 720     1.78                                                                  392                                       ______________________________________                                         *Values given for CPS @ 20 and 50                                        

                  TABLE 3                                                         ______________________________________                                        Analysis of Cottage Cheese Samples                                                   Sample                          Solubility                             Test   Information PH      TTA   Protein                                                                             Index                                  ______________________________________                                        1      Example 1 milk                                                                            6.20    0.26  15.56 2.00                                          Cottage Cheese                                                         2      1% Lowfat   6.52    0.10  14.38 1.75                                          Cottage Cheese                                                         ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        Analysis of cottage cheese whey samples                                                     Example 1 Milk                                                                          1% Milk                                               ______________________________________                                        Fat by Mojonnier                                                                              1.09        0.75                                              Solids 100C/Vacuum                                                                            92.7        95.83                                             Protein         8.18        7.32                                              Ash             9.16        8.84                                              TTA             3.46        3.56                                              ______________________________________                                    

EXAMPLE 4 Production of Buttermilk

Milk made according to Example 1 was pasteurized at 79° C. for 5minutes, cooled at 20° C. and inoculated with lactic acid starterculture. The culture contained S. cremoris, L. citrovorum and S.diacetvlactis at the 0.5% level by weight and 0.1% by weight salt wasalso added. After adding culture and salt, the mixture was incubated at22° C.±1° C. for 16 hours. The resultant products were analyzed; thedata obtained is reported in Table 5. As can be seen from the datapresented therein, the buttermilk product made with the example 1 milkhad nice body and appearance, with less acidity than the controls, whichwere made with skim milk and 1% milk.

                  TABLE 5                                                         ______________________________________                                        Analysis of Buttermilk samples                                                        Sample                                                                Test    Information pH         TTA  Protein                                   ______________________________________                                        1       1% Lowfat   4.60       0.54 3.31                                              Buttermilk                                                            2       Skim Milk   4.85       0.49 3.41                                              Buttermilk                                                            3       Example 1 milk                                                                            4.62       0.59 3.35                                              Buttermilk                                                            4       Sealtest    4.40       0.66 3.24                                              Buttermilk                                                            ______________________________________                                    

EXAMPLE 5 Production of Hard Cheese and Whey

Milk made according to Example 1 was pasteurized (79° C. for 5 minutes)cooled to 20° C. and inoculated with lactic acid starter culture. Theculture contained S. lactis at a 5% level by weight and 0.2% level byweight rennin. After adding the culture and rennin, the mixture wasincubated at 32° C.±1° C. for 5 hours (short-set method). Afterfermentation, the curd was heated at 40° C.±1° for 35 to 45 minutes, andthe whey was collected separately. The matted curd was transferred tocheese cloth to remove further whey and refrigerated. The liquid wheywas dried at 55° C.±2° C. for 48 hours. Data generated from analysis ofthe cheese as well as hard cheese produced under the same conditionsfrom 1% milk are shown in Table 6. The hard cheese had a nice creamytexture.

                  TABLE 6                                                         ______________________________________                                        Analysis of cheese products                                                   Example 1     1% Lowfat Milk                                                  ______________________________________                                        Protein    25.78  24.85                                                       pH          4.66  5.34                                                        TTA         1.58  0.34                                                        ______________________________________                                    

What is claimed is:
 1. A method for producing a low fat, low cholesteroldairy product selected from the group consisting of cottage cheese,cheddar cheese, condensed whey, yogurt and buttermilk, wherein saiddairy product has a taste and mouthfeel that approximates the taste andmouthfeel of a product prepared from whole or 2% milk,comprising:preparing a premix by combining about 50 to about 70%non-tropical vegetable oil, about 15 to about 20% food grade gum, about6 to about 10% of a flavoring agent and about 6 to about 10% of a nonlauric emulsifier; adding about 1% to about 5% of said premix to about99% to about 95% skim milk to form a mixture of said premix and saidskim milk; pasteurizing and homogenizing said mixture; and processingsaid mixture to produce a low fat, low cholesterol dairy productselected from said group of dairy products.
 2. A method according toclaim 1 wherein said non-lauric emulsifier comprises about 35 to about45% mono and diglycerides, about 23 to about 43% sodium stearoyllactylate and about 12 to about 32% polysorbate
 60. 3. A methodaccording to claim 1 comprising inoculating said mixture with lacticacid bacteria to produce a yogurt dairy product.
 4. A method accordingto claim 1 comprising inoculating said mixture with lactic acid starterculture to produce a cottage cheese dairy product.
 5. A method accordingto claim 1 comprising inoculating said mixture with lactic acid starterculture to produce a buttermilk dairy product.
 6. A method according toclaim 1 comprising inoculating said mixture with lactic acid starterculture to produce a hard cheese dairy product.